The Hawaii Department of Transportation is pulling an old project back off the shelf, restarting plans to extend the Daniel K. Inouye Highway across South Kohala with a roughly 10.5-mile addition from its current end at Māmalahoa Highway to Queen Kaʻahumanu Highway. The agency says it will reopen environmental reviews and kick things off with an informational open house in Waikōloa on May 20 to gather public comment.
In a news release, HDOT said it is working with the Federal Highway Administration to prepare updated Environmental Impact Statements under both the National Environmental Policy Act and Hawaiʻi’s HEPA. The department also plans to roll out a new project website and a series of public meetings. The updated EIS will refine alternatives first studied in a 2017 draft, and the Waikōloa session is set for 6 to 8 p.m., where maps and project materials will be laid out for residents to pore over, according to the Hawaii Department of Transportation.
Why the state is restarting the push
DOT officials and local lawmakers tie the revival to both safety concerns and the changing funding landscape. The extension was shelved in fall 2020 after state funding sources dried up and a hoped-for federal grant did not materialize, and the department has since been hunting for new revenue streams and federal partners. Lawmakers appropriated roughly $3 million in 2024 to finish the environmental work, a move DOT leaders say will let them pick up where the 2017 draft EIS left off, per reporting by the Hawaii Tribune-Herald.
Cost, timeline and federal interest
DOT spokesperson Shelly Kunishige has pegged the updated rough price tag for the extension at about $150 million, and the agency is coordinating with the Federal Highway Administration to chase federal funding. Officials have also flagged potential defense-related funding and a possible “defense access road” designation, since the route would tighten up access near the Pohakuloa Training Area. These details were reported by the Honolulu Star-Advertiser.
History and traffic forecasts
The idea is hardly new. The Federal Highway Administration’s 2017 draft EIS ran through three possible alignments and projected substantial traffic growth on the corridor, using forecasts through 2035 to weigh the options. That federal draft laid out route maps, traffic modeling and construction-cost estimates that shaped early talks over right-of-way and mitigation. More recent DOT traffic models cited in local reporting show higher volumes along parts of the existing route, which DOT officials say bolsters the case for revisiting the project. See the Federal Highway Administration draft EIS for the original analysis.
What’s next for neighbors and travelers
For residents and business owners, the first round of outreach is expected to home in on route alternatives and potential impacts on cultural sites, wildlife and local roads. HDOT says the Waikōloa open house will feature maps and a project timeline, and that more meetings will follow as the environmental review moves forward. The department is urging the public to turn out on May 20 and to keep an eye on the new project website for updates and comment opportunities. For more details and the open house flyer, see the release from the Hawaii Department of Transportation.
